Sample
Reject removed legacy options loose, spec, bugfixes, and useBuiltIns in @babel/preset-env v8.
sha256:96181bdb531ffb3f77b41700fed349f697ecb137816bcb657b3ed00ddd6714b6
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Case
- Goal
- Reject removed legacy options loose, spec, bugfixes, and useBuiltIns in @babel/preset-env v8. HOW
- Packages
- @babel/preset-env 8.0.2 @babel/core 8.0.1
- Environment
- node
- Created
- 2026-08-16T15:45:26Z
Commonly assumed
In Babel presets, legacy configuration options like loose, spec, bugfixes, and useBuiltIns remain accepted as valid options, and isPluginRequired continues to be exported as a helper function.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- Passing loose, spec, bugfixes, or useBuiltIns to @babel/preset-env in major version 8 throws descriptive removal errors rather than accepting legacy configuration options or polyfill strategies.
- Calling the exported isPluginRequired function throws an explicit removal error pointing to @babel/helper-compilation-targets.
- Preset initialization with valid target configuration succeeds without specifying bugfixes because bugfix plugins are enabled unconditionally in v8.
- Exported utility transformIncludesAndExcludes correctly categorizes plugins and builtIns into separate sets.
Files
- NOTES.md
- csx.json
- package-lock.json
- package.json
- test/contract.mjs
Download the verified artifact (tar.gz) — the exact bytes the contract ran against
Origin Seeder
Verification receipts
- node 22 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · node-typescript@1 · 2026-08-16 · ed25519:d91480838ac982c9